Clean Install Fails

I want a multi-boot system - existing XP-home - and Vista just to have a look
at it
(I'm a PC salesman and will no doubt have to sell PCs with Vista early next
year)

I tried and failed - any advice on how to create this, or what went wrong
please.

I shuffled by partitions and created an empty 50GB primary partition (Drive
G, using partition manager under XP home, (fully updated).
XP still boots - so made a backup.
Downloaded RC1, created DVD and ran Custom Install - set to load into the
emty partition. Update was enabled.
Vista loaded, a multi-OS boot screen was automatically created as part of
the install - I didnt have to select anythingd and selecting Vista at boot
time loaded vista and worked. OK some issues with drivers - see below.
Eventually I decided to return to XP so shut down and re-booted and selected
'Old Windows System' from the multi-boot options - and heres where the
problems started.

XP failed to start - black screen, white text, '<windows
root>\system32\hal.dll corrupt or missing'

Tried again - same
Tried with Vista - it started

So - now what -
recovered my backup to C. - same error message.

Thought it could be a corrupt boot - so tried to re-install XP from CD
CD started and eventually - blue screen of death, 'Stop' error caused by
pci.sys.

Booted old DOS disk and used FDISK - deleted XP and VISTA partitions - still
can not run XP Install.
Deleted ALL partitions - same
Used old Norton DISKEDIT to wipe out scetor zero - same.

OK - got out PC manufacturers recovery disks and booted - it detected the
corrupt boot sector, rebuilt - and bingo - back to scratch
Used Partition manager to recreate partions, recovered my backup again and
TADA - it works - but what a palaver.

Vista driver issues
Upgrade tool advises after installing Vista to get new CREATIC 802.11G
driver - but I cant find one.
Sound dead - upgrade adviser suggests this may be the case - its is a
C-Media High Definition Audio - codec CMI9880L - cant find drivers
TV Tuner - no go - it is a Medion card with the 7134 chip set - cant find
drivers
These arnt an issue as I dont use the wireless, TV or sound very often, and
I just want to get a feel for Vista.